Cell phone users, for example, can not only conduct the usual voice phone calls but also have access to a wide variety of additional facilities based on digital data carrying services provided by mobile phone carriers. Cell phones users can, for example, transmit text messages to one another, send and receive email using the Internet , and browse the World Wide Web either through proprietary interfaces or direct access to Internet servers. One use of these services is to download content such as ringtones and video games. In the word “content” we include images, text messages, video material, sounds, audio material, programs, and web pages. Sounds may include ringtones, which play when a user receives a call, and ring-back tones, which are played to a caller to inform them of the recipient's phone is ringing. Another use is to subscribe to services that automatically transmit content to a user periodically. Although user devices designed specifically to take advantage of such functions sometimes include larger screens than hand-held devices, standard QWERTY-layout keyboards, and faster-than-normal data connection capabilities, cell phones with small screens and numeric keypads are also capable of accessing these data services.
Integrated Voice Response (IVR) systems enable users of telephone or other voice-based communications technologies to interact with databases and other information resources using their voices and touch-tone signals generated by their phones. In telephone banking, for example, a bank account holder may access his accounts by speaking his account number and other identifying information or by entering numbers on his phone's keypad. The IVR not only provides an interface for user interaction, but also acts as an intermediary by interpreting the user's speech or touch-tones generated by his phone, relaying the entered information to the bank's computer systems, and converting the bank's response into speech that the user can understand over the phone.